You can install Minecraft Forge for free from the Forge website, and then use it to download and enable mods.
You can install mods in "Minecraft" by playing the "Java Edition" and using the third-party app Minecraft Forge.
PC version only. Most mods are for the Windows release of Borderlands 4. Close the game before adding/removing mods. Install and test one mod at a time and avoid overlapping replacers of the same ...